Combination drug: Prempro
Medroxyprogesterone is a semisynthetic compound that differs in structure from the naturally occurring human hormone progesterone. It is added to estrogen replacement therapy to prevent uterine cancer caused by unopposed estrogen. It is also used to treat absence of menstrual bleeding (amenorrhea) and abnormal menstrual bleeding. Medroxyprogesterone is available alone and in a combination product. An injection product is used for contraception.
Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem contradictory. For clarification, read the full article for details about the summarized interactions.
 Check: Other—Before taking any of these supplements or eating any of these foods with your medication, read this article in full for details. | Folic acid Magnesium Vitamin A Vitamin D Zinc |
| Depletion or interference | None known |
| Side effect reduction/prevention | None known |
| Supportive interaction | None known |
| Reduced drug absorption/bioavailability | None known |
| Adverse interaction | None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Dietary Supplements
Vitamin A and folic acid
In a one-year study of predominantly malnourished women in India and Thailand, medroxyprogesterone used for contraception was associated with increased blood levels of vitamin A and folic acid.1 The clinical meaning of these changes remains unclear.
Zinc and magnesium
In a group of 37 postmenopausal women treated with conjugated estrogens and medroxyprogesterone for 12 months, urinary zinc and magnesium loss was reduced in those women who began the study with signs of osteoporosis and elevated zinc and magnesium excretion.2 The clinical significance of this interaction remains unclear.
Vitamin D
In a study of postmenopausal women, treatment with estrogen alone increased vitamin D blood levels, whereas estrogen plus medroxyprogesterone lowered vitamin D back to the level seen without estrogen use.3 This outcome might suggest that medroxyprogesterone interferes with beneficial effects estrogen may have on vitamin D metabolism and vitamin D supplementation would be called for. However, some research has not found the addition of vitamin D to estrogen/progestin combinations to be helpful.4 Therefore, while many doctors recommend 400 IU vitamin D to women taking estrogen/progestin combination hormone products, the efficacy of such supplementation has not been proven.
References
1. Joshi UM, Virkar KD, Amatayakul K, et al. Impact of hormonal contraceptives vis-a-vis non-hormonal factors on the vitamin status of malnourished women in India and Thailand. World Health Organization: Special Programme of Research, Development and Research Training in Human Reproduction. Task Force on Oral Contraceptives. Hum Nutr Clin Nutr 1986;40:205–20.
2. Herzberg M, Lusky A, Blonder J, Frenkel. The effect of estrogen replacement therapy on zinc in serum and urine. Obstet Gynecol 1996;87:1035–40.
3. Bikle DD, Halloran BP, Harris ST, Portale AA. Progestin antagonism of estrogen stimulated 1,25-dihydroxyvitamin D levels. J Clin Endocrinol Metab 1992;75:519–23.
4. Komulainen M, Tuppurainen MT, Kroger H, et al. Vitamin D and HRT: no benefit additional to that of HRT alone in prevention of bone loss in early postmenopausal women. A 2.5-year randomized placebo-controlled study. Osteoporosis Int 1997;7:126–32.
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2006-09-07
